Radio receiving system



m R A R E G V. a

RADIO RECEIVING SYSTEM Film July a, 1939 2 Sheets-,Sheet l T0 AUDID AHPUFIER PLATE SUPPLY INVENTOR Gennaro lf'er da' ATT RNEY G. v. GERARDI 2,185,336

RADIO RECEIVING SYSTEM Filad July B, 1958 2 Sheets-'Sheet 2 INVENTOR Gennaro Vyef'ar''a' A ORNEY Patented Jan. 2, 1940 RATENT OFFHCE RADIO RECEIVING SYSTEM Gennaro V. Gerardi, Boston, Mass.

Application July 8, 1938, Serial No. 218,041

9 Claims.

The present invention relates to a radio receiving system and it particularly relates to a radio receiving system having enhanced compaotness.

In the usual type of radio receiving system now in utilization it is necessary to use a relatively large number of tubes to obtain satisfactory reception and reproduction and it is also usually necessary to have rather large or elongated outside aerials which either must be strung around within the room or be connected to an extension outside of the building structure.

It is among the particular objects of the present invention to provide an improved andmore compact radio receiving set construction in which the entire system may operate with the most satisfactory reception and reproduction with a minimum number of tubes and without the necessity of extensive external aerial constructions.

Other objects will be obvious or will be readily apparent during the course ofthe following specication.

In accomplishing the above objects it has been found most satisfactory to provide a double loop antenna, the loops of which may be mountedl so that both of the loops maybe rotated and/or so that one of the loops may be rotated within the other. This double loop antenna may be compactly positioned within the confines of the radio cabinet or radio set casing itself without the necessity of external connections.

In the preferred construction, the external loop, which may be square or rectangular, may act as a pick-up coil or antenna and also as a primary to the inner rectangular or square loop. The inner loop may act also as a secondary or tickler and both loops may be rotated together for directional purposes or at slight angles to one another.

The ends of the external loop preferably are connected to the grid and ground, while the internal loop may be connected in the plate circuit and also tapped to make connection to the grid of the same tube, thereby causing a feed back from the plate to the grid. This connection from the inner loop to the plate circuit may be controlled by resistances and variable condensers if desired.

By the use of this loop construction it is possible wholly or largely to eliminate radio `frequency amplication, if desired. Audio frequency amplification systems however may be included in order to get volume.

In the drawings which show several specific embodiments of the present invention by way of illustration, but to the details of which the pres- (Cl. Z-20) ent invention is by no means restricted, since many changes and alterations are possible.

Fig. 1 is a diagrammatic view of one wiring arrangement showing the loops positioned side by side connected to a three-element tube,

Fig. 2 represents another diagram illustrating the connections of the two lloops to a multi-element tube,

Fig. 3 is a complete wiring diagram illustrating a complete circuit includingthe necessary am- 10 plication circuits which may be added to the primary circuit of the present invention.

Fig. 4 is a perspective View showing the loop construction.

Referring to Fig. 1, the loop l0, constituting an 15 inductance, may be square or rectangular, if desired, and it may act not only as a pick-up coil and antenna, but also as a primary for the inside loop ll, which if desired may be independently rotatably mounted in respect to the loop 20 lll.

In Fig. 4 is shown the outer loop l0 and the invner loop I l both of which loops may be wound in groups as indicated at l5!) andl l5l amounting to anywheres from '2 to 10 turnsv per group, as ndi- 25 cated at |50 and l5l, upon boxlike structures l52 and 153. Both structures i552 and Hit may `loe positioned on the turn table i541 which may have a ball bearing mountl |55 upon the base l56. The loop structure ll may be rotated to 30 be set at a different position in respect to the loop structure ll) and then the two loop structures may be xed in position in respect to each other by means of the lock'nuts l51, the handle 53 permitting movement or turning of 35 the combined loop structure lll and li.

The loop ll acts as the secondary or tickler. One end l2 of the loop lll is connected to the grid I3 of the tube M, while the other end l5 may be connected to the thermionic emitting ele- 40 ment I6 which is provided with a heating filament l'l.

This same end may also be connected through the condenser Ilia` and the variable resistance l1 to the minus plate supply i8. A connection I9 45 between the ends l2 and l5 of the antenna Ill may contain the Variable condenser 2li.

The inner loop Il has one end 2l connected to the plus plate supply 22; The loop Il is also tapped at 23 and connected through the lead 24 50 and the variable condenser 25 to the end l2 of the outside loop l0.

This circuit, as just described, shows the basic arrangement of the novel circuit herein and with such circuit there is assurance that there will be 55 maximum reception and high reproduction with great compactness.

In the diagram of Fig. 2 the outer loop I0 and the inner loop l l' are connected in an equivalent manner, as shown in Fig. l, with the loop l0' consttuting the inductance and the loop i l' constituting the secondary or tickler.

One end 3Q of the loop i9 is connected to the grid 3l of the tube structure 32 and the other end 33 is connected to the ground 34- or to the minus of the plate. supply 3d in the same manner as shown in Fig. 1.

The outside loop lli is preferably tuned by the variable condenser 36 which is placed upon the lead 3l' connected to the' ground 33;

It Will be noticed that the conductor 3? is also connected at 3S to the leg 3!! oi the outside loop lll', which leg 3S is connected to the grid 3f. If desired, the lead 3l' at the groundend could Ibe conducted to the minus plate supply, indicated The inside loop it is connected in the circuit of the plate d@ by the connection di. The other end of the loop il" is connected at ft2 to a radio frequency choke and at Mi to the positive plate sup-ply where it may also be connected' to a lead' to the audio amplifying circuit.

The loop l E is shunted by the condenser i5 and the radio freoprencyk choke il upon the connection 46'.

The loop llis also* tapped at d8 through the resistance 49T, the fixed condenser 5G and the variable condenser 5 Ef and this tap then connects to the lead 52. The lead 52 is connected at one side to the auxiliary grid 53 and at the other side at 5dv to the connection 55 from the lead 46 tothe l'ead 56.

The tapped` connection at 48' primarily controls the regenerative circuit. The variable resistance 5T upon the connection 56S controls the feed backl through the condenser 58.

It will be noted that the connections 55 and 56 are also provided With a resistance 59 and a condenser Ell, respectively. The other side of the variable resistance 5l is connected' to the ground at 6l.

In the complete layout circuit of Fig. 3, which shows an audio amplifier circuit, to which the present invention is by no means limited, in connection With the structure of thev present application, the outside loop M32 and` the inside loop H 2 may be connected in substantially the same manner as shownin Figs. 1 and 2.

It Will be noted that in Fig. 1 the connections are designed for a four element tube having plate voltage supplied by batteries. In Figs. 2 and 3, on theY other hand, the connections are for a ve element tube which may be operated from an A. C. or D. C. potential source with the plat supply taken from said source. f

As indicated in Fig. 3r one end of the coil |02 may be connected to the ground 342 or to the negative plate supply, not shown.

The other endV of the coil H32 is connected by the conductor 392 to the grid connection 3l2.

The connections to the heating filament T02 for the cathode or electron emitter 122 are not shown.

The main tube 322 also has a plate connection 4i 2 from one side of the inside loop l I2. The tap 482 of the inside loop l I2 is connected through the resistance 92, the ixed capacity 502 and the variable capacity 5 l2 to the connection .'522vvhich leads to the secondary grid indicated by the letters Gs.

The connections in Fig. 3 show how the construction of the present application may be utilized in combination with a typical audio amplier circuit. This circuit includes the tubes and 8|, the electrical plug connection 82, and the speaker construction 83.

The invention is not intended to be restricted to any particular construction or arrangement of parts nor to any particular application of any such construction', nor to any specic method of operation or manner of use, or to any of the various details thereof, herein shown. and described as the same may be modified in various vparticulars or be applied in many varied relationships without departing from the spirit and scope of thev claimed invention, the practical embodiments herein illustrated and described merely showing some of the various features entering into the application of the invention.

What is claimed is:

1'. A radio receiving system comprising an enclosed compact aerial arrangement having an outer loop and an inner loop independently rotatably mounted inside of each other and an electron tube having grid, filament and plate electrodes, the end connections of the outer loop beingconnected to the grid and filament electrodes and the end connections of the inner loop being connected to the plate and to the positive plate voltage supply, and said inner loop having an intermediate tap connection to the grid, said tap connection being to a portion of the inner loopintermediate of the ends thereof, and said tap connection including a tuning condenser for said inner loop.

2; A radio receiving system comprising an enclosed compact aerial arrangement having an inner loop and an outer loop and a tube connected to said inner and outer loops, said tube having a thermionic emitter, grid and plate elements, one end of said inner loop being connected tothe plate and the other end of said same loop being connected to they plate voltage supply and a tap from said inner loop connected to said grid element and the other outer loop being connected to the grid and to the thermionic emitter element, said tap including a condenser and said tap being to a portion'of said inner loop intermediate the connectionsV of said inner loop to the plate and to the source of supply to the grid.

3. A radio receiving system comprising an electron discharge tubing being provided with a thermionic emitter, a plate and a grid rotatably mounted inner and outer loops, said inner and outer loops being adjustable in respect to each other,v the outer loop being connected to the grid and thermionic emitter of a tube and the outer loop being connectedrto the plate and to the positive voltage supply of the plate and a tap from an intermediate portion oi said inner loop to said grid', said connection being provided with a variable condenser, said tap including a condenser and said tap being to a portion of said inner loop intermediate the connections of said inner loop to the plate and to the source of supply to the grid.

4. In a radio receiving system of the type having a tube with the grid, a thermionic emitter and a plate, and positive and negative voltage connections for the plate; an enclosed compact aerial connection comprising an outer loop and an inner loop, the outer loop being connected to the thermionic emitter and the inner loop being connected to the plate and both loops also being connected to the grid, said inner loop having a tap connection to said grid and the inner loop being also connected to the positive plate voltage connection, said tap connection being to a portion of the inner loop intermediate of the ends thereof, and said tap connection including a tuning condenser for said inner loop.

5. In a radio receiving system of the type having a tube with the grid, a thermionic emitter and a plate, and positive and negative voltage connections for the plate; an enclosed compact aerial connection comprising an outer loop and an inner loop, the ends of the outer loop being connected to the grid and the emitter and the ends of the inner loop being connected to the plate and the positive voltage connections and the inner loop having an intermediate tapped connection to the grid, said connection including a tuning condenser for said inner loop.

6. In a radio receiving system of the type having a tube With a grid, a thermionic emitter and a plate, and positive and negative voltage oonnections for the plate; an enclosed compact aerial connection comprising an outer loop and an inner loop, the ends of the outer loop being connected to the grid and the emitter and the ends of the inner loop being connected to the plate and the positive voltage connections and the inner loop having an intermediate connection to the grid, said connection including a tuning condenser for said inner loop, the end of the outer loop connected to the filament being also connected to the negative Voltage connection through a variable resistance.

7 In a radio receiving system of the type having a tube With a grid, a thermionic emitter and a plate, and positive and negative voltage connections for the plate; an enclosed compact aerial connection comprising an outer loop and an inner loop, the ends of the outer loop being connected to the grid and the emitter and the ends of the inner loop being connected to the plate and the positive Voltage connections and the inner loop having an intermediate connection to the grid, said connection including a tuning condenser for said inner loop, the ends of the outer loop being shunted by a connection including a variable condenser.

8. Radio receiving apparatus comprising in combination an electron tube having grid, lament and plate electrodes, an input circuit including said grid and ilament electrodes, an output including said plate and lament electrodes, and a pair of radio frequency energy collecting loops superimposed upon each other and including an outer loop and an inner loop, the ends of the outer loop being connected to the grid and filament electrodes and the ends of the inner loop being connected to the plate and the positive plate voltage supply, and said inner loop also having an intermediate tap connection to the grid, said connection also including a variable capacity for tuning the inner loop.

9. Radio receiving apparatus comprising in combination an electron tube having grid, lament and plate electrodes, an input circuit including said grid and filament electrodes, an output including said plate and filament electrodes, and a pair of radio frequency energy collecting loops superimposed upon each other and including an outer loop and an inner loop, the ends of the outer loop being connected to the grid and lament electrodes and the ends of the inner loop being connected to the plate and the positive plate voltage supply, said inner loop also having an intermediate tap connection to the grid,

said connection also including a variable capacity for tuning the inner loop and mounting means permitting independent adjustment of said loops in respect to each other and also permitting joint adjustment or both loops together, said inner loop being positioned inside of said outer loop.

GENNARO V. GERARDI. 

